非小细胞肺癌脑部转移瘤适形与调强放疗的剂量研究

为探讨NSCLC脑部转移瘤调强放疗与适形放疗的剂量特点,本研究选取57例非小细胞肺癌脑转移瘤患者,其中单个脑转移灶患者5例,多个脑转移灶患者52例,分别设计全脑放疗+适形放疗与调强放疗计划,用均匀指数(HI)和适形指数(CI)评价靶区剂量,危及器官(OAR)剂量用近似最大剂量D_2%(串联)和中位剂量D_50%(并联)进行评价。研究发现,单个脑转移灶IMRT与WBRT+CRT比较中,CI为(PTV,(0.80±0.15) cGy,(0.34±0.19) cGy, p=0.00),HI为(PTV,(0.52±0.03) c Gy,(0.71±0.12) cGy, p=0.24),两者OARs剂量比较:脑干为((4 348±236) cGy,(4 593±149) cGy, p=0.01),脑垂体为((4 258±166) cGy,(4 581±123) cGy, p=0.02);在多个脑转移灶中,IMRT与WBRT+CRT比,较CI为(PTV,(0.59±0.33) cGy,(0.49±0.27) cGy, p=0.03),HI为(PTV,(0.93±0.01) cGy,(0.58±0.03) cGy, p=0.19),两者OARs剂量比较:脑干为((4 946±132) cGy,(4 843±196) cGy, p=0.51),脑垂体为((4 597±180) cGy,(4 705±149) cGy, p=0.70)。本研究的结果说明,单个脑转移灶患者,IMRT较WBRT+CRT有更好的靶区适形性、稍差的靶区异质性,脑干和垂体的IMRT剂量低于WBRT+CRT,而眼球、晶体的剂量两者差别不明显。多个脑转移灶患者,IMRT较WBRT+CRT有更好的靶区适形性、稍差的靶区异质性,而OARs剂量,IMRT较WBRT+CRT差异不明显。在临床实践过程中,应当根据患者不同的病灶情况选择合适的放疗方案,以获取更优的临床治疗效果。     

调强适形放疗联合化疗治疗局部晚期食管癌的疗效观察

目的:观察调强适形放疗(intensity modulated radiation therapy,IMRT)联合多西他赛、奈达铂方案化疗同步治疗局部晚期食管癌的疗效及安全性。方法:选择66例局部晚期食管癌患者为研究对象,将其随机分为2组,其中常规放疗组(A组)共30例,采用常规照射方法,6/8 MV高能X线,2.0 Gy/次,5次/周;40 Gy/20次后再次定位剂量达60~66 Gy,强调放疗组(B组)共36例,采用强调适应性放疗,6/8MV-X射线照射,以95%等剂量线包绕PTV(计划靶区),处方剂量GTV(肿瘤区)66 Gy/30次,CTV(临床靶区)60 Gy/30次,PTV 60 Gy/30次,每天1次,每周5次。强调放疗组同期接受IMRT和多西他赛、柰达伯化疗,21天1个周期,连续2个周期。治疗结束后根据实体瘤疗效评价标准(RECIST)评定临床疗效;参照WHO毒性反应分度标准评价毒副反应。结果:常规放疗组和强调放疗组的总有效率分别为46.66%和91.67%(x2=17.26,P0.05);常规放疗组的毒副反应发生率显著高于强调放疗组,包括骨髓抑制、放射性食管炎和消化道反应的发生率存在显著差异(P0.05)。结论:调强适形放疗联合多西他赛、奈达铂化疗同步治疗局部晚期食管癌疗效较好,毒副反应可耐受,具有潜在的推广应用价值,值得临床进一步研究。     

Emergence of cooperative linkages by random intensity of selection on a network

By assuming the random intensity of selection, the emergence of cooperation on a network is studied. We constructed an evolutionary model in which an individual plays the prisoner's dilemma game, and updates both its strategy and neighbor connections in response to its relative success in the game. The constant (strong or weak) and random intensities of selection are compared. The random intensities of selection are introduced to realize complex environmental effects on the fitness of each individual. Breaking the links on the network is realized according to fixed global parameters. We found that cooperative clusters emerged when cooperators unilaterally broke the link with defectors. The emergent networks under these conditions had a high clustering coefficient and shared some properties with a scale-free network. In addition, after a cooperator with high fitness emerged circumstantially under the random intensity of selection, we observed that the cooperative linkages emerged and spread rapidly through the network. This situation frequently occurred because of the stochastic effect on the fitness of cooperators. Thus, the origin of such phenomena is qualitatively different from the Lotka-Volterra system in which deterministic processes control the system. Cooperative linkages spread more when defectors maintained many links with cooperators.     

The effects of heat-induced pain on the detectability,discriminability, and sensation magnitude of vibrotactile stimuli

The effects of heat-induced pain on absolute thresholds, sensation magnitudes and amplitude-difference thresholds were measured at 10 and 100 Hz. Consistent with previous results, heat-induced pain elevated the absolute thresholds by approximately 8.0 dB and lessened the magnitudes of tactile sensations during pain as compared to the non-painful condition. In contrast to these effects, the discriminability of change in the intensity of the vibrotactile stimuli was unaffected by the presence of pain indicating that the effect of pain on tactile sensations is more likely due to sensory rather than cognitive processes (i.e., attention) and that the mechanisms underlying tactile sensitivity as compared to discriminability are different.     

Estimating population size for a continuous time frailty model with covariates in a capture-recapture study

A continuous time frailty capture-recapture model is proposed for estimating population size of a closed population with the use of observed covariates to explain individuals' heterogeneity in presence of a random effect. A conditional likelihood approach is used to derive the estimate of parameters, and the Horvitz-Thompson estimator is adopted to estimate the unknown population size. Asymptotic normality of the estimates is obtained. Simulation results and a real example show that the proposed method works satisfactorily.     

Does BMI predict the early spatial variation and intensity of Covid-19 in developing countries? Evidence from India

This paper studies BMI as a correlate of the early spatial distribution and intensity of Covid-19 across the districts of India and finds that conditional on a range of individual, household and regional characteristics, adult BMI significantly predicts the likelihood that the district is a hotspot, the natural log of the confirmed number of cases, the case fatality rate, and the propensity that the district is a red zone. Controlling for air-pollution, rainfall, temperature, demographic factors that measure population density, the proportion of the elderly, and health infrastructure including per capita health spending and the proportion of respiratory cases, does not diminish the predictive power of BMI in influencing the spatial incidence and spread of the virus. The association between adult BMI and measures of spatial outcomes is especially pronounced among educated populations in urban settings, and impervious to conditioning on differences in testing rates across states. We find that among women, BMI proxies for a range of comorbidities (hemoglobin, high blood pressure and high glucose levels) that affects the severity of the virus while among men, these health indicators are also important, as is exposure to risk of contracting the virus as measured by work propensities. We conduct sensitivity checks and control for differences that may arise due to variations in timing of onset. Our results provide a readily available health marker that may be used to identify and protect especially at-risk populations in developing countries like India.     

Interaction of recombinant CanPIs with Helicoverpa armigera gut proteases reveals their processing patterns,stability and efficiency

Six diverse representative Capsicum annuum (common name: hot pepper; Solanaceae) protease inhibitor genes, viz CanPI‐5, ‐7, ‐13, ‐15, ‐19, and 22 comprising 1–4 inhibitory repeat domains (IRDs), were cloned and expressed in Pichia pastoris. The recombinant proteins were evaluated for their interactions with bovine trypsin, chymotrypsin, and Helicoverpa armigera gut proteases (HGP) using electrophoretic (native and denaturing) and mass spectrometric (MALDI‐TOF‐MS in combination with intensity fading assays) techniques. These techniques allow qualitative and semiquantitative analysis of multiple and processed IRDs of purified recombinant Capsicum annuum proteinase inhibitor (rCanPI) proteins. rCanPIs showed over 90% trypsin inhibition, varying chymotrypsin inhibition depending on the number of respective IRDs and over 60% inhibition of total HGP. rCanPI‐15 that has only one IRD showed exceptionally low inhibition of these proteases. Interaction studies of rCanPIs with proteases using intensity fading‐MALDI‐TOF‐MS revealed gradual processing of multi‐IRD rCanPIs into single IRD forms by the action of HGP at the linker region, unlike their interactions with trypsin and chymotrypsin. Intensity fading‐MALDI‐TOF‐MS assay showed that CanPI‐13 and ‐15, possessing single IRD and expressed predominantly in stem tissue are degraded by HGP; indicating their function other than defense. In vitro and in vivo studies on rCanPI‐5 and ‐7 showed maximum inhibition of HGP isoforms and their processed IRDs were also found to be stable in the presence of HGP. Even single amino acid variations in IRDs were found to change the HGP specificity like in the case of HGP‐8 inhibited only by IRD‐12. The presence of active PI in insect gut might be responsible for changed HGP profile. rCanPI‐5 and ‐7 enhanced HGP‐7, reduced HGP‐4, ‐5, ‐10 expression and new protease isoforms were induced. These results signify isoform complexity in plant PIs and insect proteases.     

A model of plant-to-plant movement of aphids: A new approach

1. A stochastic model was applied to the changes in the distribution of aphids on plants in a field determined by their plant-to-plant movements.
2. The expected numbers of aphids on plants were calculated for the 5 days of an experiment reported byShiyomi (1967) and compared with observed frequencies at these times.

     

41例初治鼻咽癌调强放疗急性不良反应临床观察

目的:观察调强放疗(intensity modulated radiation therapy,IMRT)对初治鼻咽癌的近期临床疗效急性毒性反应.方法:41例初治鼻咽癌患者中,按92福州分期标准,Ⅰ期1例,Ⅱ期4例,Ⅲ期13例,Ⅳ期23例;1例仅接受根治性调强放疗,其余40例均接受放化综合治疗.鼻咽大体肿瘤体积(GTVnx)处方剂量为(68～70) Gy分30～33次,颈部淋巴结(GTVnd)处方剂量为(62～66)Gy分30～33次,临床靶体积1(CTVl) (60～64) Gy分30～33次,临床靶体积2(CTV2) (50～54) Gy分30～33次.病灶靶区处方剂量为68～70 Gy.对于鼻咽癌Ⅱ、Ⅳ期患者,IMRT治疗的同时,根据淋巴结转移,以及患者的基本情况,酌情给予奈达铂+5-Fu,进行1～2周期的诱导化疗,以及单药奈达铂的同步化疗.根据RTOG /EORTC标准,对其急性反应进行评估.结果:中位随访时间1～13个月,多数患者仅表现为1～2级急性反应,观察到4级急性反应l例.1年随访期间,局部区域进展、远处转移,以及总生存率分别为95.1％、95.1％和100.0％.结论:对于早期或晚期鼻咽癌患者,IMRT均可获得理想的剂量分布,最大可能地保护正常组织,提高患者对毒副反应的耐受力,明显提高治疗的临床效果.远期疗效需进一步观察.